Thanks for getting back to me. The system was completely new as of this summer, and everything was installed clean and fresh, straight out of the box. The X-serve raid had the 1.0 update installed too, right at the start.
In response to your suggestion of using whole number keyframes for the drop shadows (instead of tenths or hundreds), I have exactly that on another image with jitters and keyframed drop shadow.
I did do another experiment that’s isolated the problem to just the “offset” parameter of the drop shadow: I had an image for which I’d keyframed offset, opacity and softness. I tried first deleting the opacity and softness keyframes and leaving the offset, and that still had jitter. I then reversed it and deleted the offset keyframes but kept softness and opacity, and the jitter was gone.
So it’s looking like a bug with the drop shadow offset keyframe alone. Any chance of a patch?
Thanks again for your help — I really appreciate it.
Becky